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Which one of the following statements about protons and photosynthesis is correct?

a. the process of electron transport concentrates protons in the thylakoid lumen.
b. the process of electron transport concentrates protons in the stroma.
c. the process of electron transport does not cause translocation of protons.

User Yarnabrina
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Final answer:

The process of electron transport during photosynthesis results in the concentration of protons in the thylakoid lumen, which are ultimately used by ATP synthase to generate ATP.

Step-by-step explanation:

The process of photosynthesis includes several key steps, one of which involves an electron transport chain (ETC). In the light-dependent reactions of photosynthesis, this chain plays a crucial role. Specifically, when photosystem II (PSII) absorbs light energy, electrons are excited and passed along the ETC, which leads to the active transport of protons across the thylakoid membrane into the lumen.

During this process, the splitting of water molecules releases additional protons into the thylakoid lumen as well as electrons that replenish those lost by PSII. Meanwhile, in photosystem I (PSI), electrons are used to reduce NADP+ to NADPH, which results in the removal of protons from the stroma. These concerted actions result in the accumulation of protons in the thylakoid lumen, thus creating a proton gradient.

This proton gradient is then used by ATP synthase to generate ATP in a process known as chemiosmosis. The movement of protons from high concentration within the thylakoid lumen to a lower concentration in the stroma (outside the thylakoid membrane) through ATP synthase provides the necessary energy to convert ADP to ATP. Therefore, it can be concluded that the process of electron transport does indeed concentrate protons in the thylakoid lumen.

User Viveksuggu
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